with that, before we get to public comment, i've invited mike bueller, executive director of san francisco architectural heritage. mr. bueller's been kind enough to sit down with me several times and we talked about a lot of these issues and i found this conversation to be very helpful. mr. bueller and we will -- if you could limit your comments to three to five minutes, that would be terrific. and then we will proceed with public comments directly after that. >> good afternoon, supervisor wiener and members of the committee on behalf of san francisco architectal heritage, threw are for this opportunity to discuss important role of historic preservation not only in the past but going forward. as heritage celebrates its 40th anniversary in the context of this hearing, i thought it would be helpful to briefly reflect on the origins of local preservation movement, its progress and setbacks over the past four decades over the challenges that still lie ahead. i would like to start by noting the preservation community is not monolithic. to be sure you will hear from a variety of perspectives tod